EPHS – Electrically Powered Hydraulic Steering - VolksPage.Net

Design and Function
KOYO
Hall sensor principle
The Hall sensor is an electronic control switch.
It consists of a rotor (magnetic ring with 60
magnets) and an integrated semiconductor
circuit in the sensor, the Hall IC.
A supply current flows through a semiconductor
layer in the Hall IC. The rotor rotates in an air
gap. As a result of the high number of magnets
in the rotor, it is possible to detect the steering
angle with a very high accuracy.
Input shaft of
steering gear
Housing of
Hall sensor
Rotor with
60 magnets
Air gap
Printed circuit board
with semiconductor
layer, Hall IC and
magnetically soft
conductor
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If a magnet of the rotor is directly within the
range of the Hall IC, this position is known as a
magnetic barrier. A Hall voltage is generated in
this state within the Hall IC at the semiconductor
layer.
The magnitude of the Hall voltage depends on
the intensity of the magnetic field between the
permanent magnets.
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U (V)
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t (s)
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As soon as the relevant magnet of the rotor
rotates further and leaves the magnetic barrier,
the magnetic field is deflected by the Hall IC.
The Hall voltage in the Hall IC drops and the
Hall IC switches off.
U 1
0
U
+ -
U 2
S
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U (V)
U 2
16
U 1
t (s)
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